New Delhi, Jul 25 (IANS): Chinese smartphone maker OnePlus has reportedly exposed hundreds of customer email addresses while sending out a mass mailer for a research study to a select number of users.

Instead of putting email IDs of customers in the "BCC" field, the company ended up copy-pasting hundreds of email addresses in the "To" field.

This resulted in all recipients of the research email receiving hundreds of customer email addresses, Android Police reported on Friday.

The exact number of users affected in this goof-up is currently unknown but one among the listed told Android Police that the number is in "hundreds".

OnePlus was yet to comment on the development.

In November last year, the company revealed a major data breach in which customer's information such as name, contact number, email, and shipping address was exposed.

OnePlus said hackers gained access to past customer orders. Exposed information included details like customer names, contact numbers, emails, and shipping addresses, but not passwords or financial details.

Before that, OnePlus reported its first security breach in which credit card information of nearly 40,000 customers was exposed through the company's official website.

OnePlus manufactures premium devices like 8 and 8 Pro and has entered into the mid-price segment with the ‘Nord' brand in India and Europe.